Rotary fan



Dec. 28, 1943. P. WAREHAM ROTARY FAN Filed Aug. 12, 1942 INVENTOR.

Pmcr W 37 Patented Dec. 28, 1943 ROTARY FAN Percy Wareham, Royal Oak,Mich assig-nor of one-half to James M. Toy, Detroit, Mich.

Application August 12, 1942, Serial No. 454,623

6 Claims.

This invention relates to rotary fans, the ob- Ject being to provide anew' and improved fan structure comprising a plate having blades on oneside of the plate arcuate in form in cross section and of a half-coneshape from the center toward the periphery and blades on the oppositeside of the fan inclined to the plane of rotation and extending at anangle to the plane of the plate and discharging air picked up inrevolution into the arcuate blades to discharge peripherally therefromin the plane of rotation of the fan.

It is further a feature and object of the invention to form the fan of asheet metal plate and to provide the aforesaid arcuate blades byattaching the same to the plate surface and to form the blades extendingoutwardly from the opposite sides of the plate by punching the plate toform the angularly disposed blades in such relationship that theangularly disposed blades in revolution of the fan pick up air anddischarge the same to the arcuate blades on the opposite side of the fanplate. Thus the arcuate blades discharge not only the air flowingthereinto by reasons of the angularly disposed blades but also airpicked up by the arcuate blades in the plane of revolution thereof.

It is also a feature and object of the invention to provide a fanstructured formed of comparatively thin sheet metal plate of circularform and the arcuate and angularly disposed blades extending on atangent from a small circle at the center of revolution to the peripheryof the circular plate forming the base or body of the fan.

These and other objects and novel features of the invention arehereinafter more fully described and claimed and the preferred form ofconstruction of a'rotary fan embodying my invention is shown in theaccompanying drawing in whicha Fig. 1 is a plan view of the dischargeface of the fan.

Fig. 2 is a section of the fan taken on line 2--2 of Fig. l and showingone manner of mounting the fan to an element for rotation thereof.

Fig. 3 is a fragmentary view showing a portion of the plate and therelationship of the arcuate and angularly disposed blades inperspective.

In the preferred form of construction my improved fan comprises a sheetmetal plate l of circular form having a central aperture to receive adriving shaft 6 and the angularly disposed blades 3 may be formed bypunching the plate I to provide blades of less width at the inner endsthan at the peripheral ends as will be understood from Figs. 1 and 3 andproviding openings 4 through the plate I. The blades 3 are disposedpreferably at an angle of approximately thirty-three and one-thirddegrees to the plane of the plate and, being of less width at the centerthan at the periphery, the volume of air picked up per revolution of theblades 3 is greater at the periphery than at the center due to thetriangular form of the blades and to the fact that the distancetravelled by the outer periphery of the angular blades per unit of timeis greater than at the inner end thereof.

The arcuate blades 5 are preferably formed of sheet metal having a fiatbase portion So attached to the plate at the rear of the opening 4 inthe direction of travel and extending rearwardly therefrom and forwardlycurved to form an arcuate portion of the form of a half-cone having itsinnermost point adjacent the center of the fan plate and providing ablade that is of increased capacity for pickup and delivery of air fromthe center toward the periphery corresponding in this respect to thecapacity of the angularly disposed blades 3 on the opposite side of theplate I. By this arrangement and form of blades air picked up by theblades 3 passes through the respective aperture 4 of the plate anddischarges into the respective arcuate blade 5 to discharge radially ofthe fan plate as indicated by the arrows in Fig. 3.

The fact that a lesser volume of air per unit of time is discharged intothe blades 5 adjacent the axis of rotation of the fan plate and anincreasing volume per unit of time at points successively greater indistance from the center of rotation provides a construction in whichthe larger volume of air discharging at the outer end of each of thearcuate blades 5 tends to cause a reduced pressure at the inner end ofthe arcuate blade resulting in a suction effect toward the said innerend and preventing discharge of air by the inner end of the blade 3outwardly of the plate surface.

This arrangement of arcuate blades of a conelike form and angular bladesof a triangular form therefore provides for discharge of greater volumeof air per revolution peripherally of the fan than would be the casewith plane faced blades on opposite sides of the fan plate as the airentering the arcuate blade 5 is caused to rotate as it enters thearcuate blade and is discharged in the form of a rotating spiral ofleast density at the inner end of the arcuate blade, the densityincreasing from the inner end of the blade toward the periphery of thefan due to the gradually increasing volume of air discharging to thearcuate blade from the companion inclined blades 3. It is this characterand relationship of blades that in my opinion provides a greater volumeof delivery of air radially from the fan per revolution than is producedby the usual fan having radial blades as my improved fan structure tendsto provide an area of least pressure at the center of the face of thefan resulting in an increased flow of air from atmosphere to the centerof rotation of the fan and where it is desired to provide a draft of airabout the occupants.

In such use the fan may be mounted on a vertical shaft 1 of a motor 8supported by a frame element 9 as indicated in Fig. 2. While an electricmotor is the preferred means for rotat- I ing the fan other means may beemployed as the invention herein disclosed is not confined to use of anyspecific driving mechanism as the features of the invention reside inthe fan structure per se.

While I have described and shown a fan embodying my invention as beingmade of sheet material such as metal it is to be understood that it maybe made of any approved material in any desired manner and that variousother changes may be made in the fan structure without departing fromthe spirit and scope of the appended claims.

Having thus fully described my invention, its utility and mode ofoperation, what I claim and desire to secure by Letters Patent of theUnited States is 1. A rotary fan comprising a flat sheet metal platerotatable on an axis at a right angle to its plane and having a seriesof apertures therein extending from near the center toward the peripheryof the plate, a fan blade having an edge attached to the rear edge ofeach aperture and inclined to the plane of the plate and extending fromthe rear of each aperture and-forwardly thereof in the direction ofrotation of the plate, a second fan blade on the opposite surface of theplate at each aperture having an edge attached to and extendingrearwardly of the rear edge of the respective aperture and thenceforwardly on a curve providing an arrangement whereby air picked up bythe inclined blades on one side of the plate is discharged into thecurved blades on opposite sides of the plate and discharged therebyradially of the fan.

2. A rotary fan comprising a comparatively thin plate rotatable on anaxis at a right angle to its plane having a series of equi-dlstantlyspaced apertures therein extending from near the center toward theperiphery of the plate, a fan blade on one side of the plate at the rearof each aperture and extending forwardly at an angle to the plate in thedirection of rotation of the plate, said blades each being of greaterwidth adjacent the periphery than at the inner ends, a second blade atthe rear of each aperture and on the opposite side of the plate fromthat occupied by the first named blades, said last named blades eachbeing of the form of a half-cone with the smaller end adjacent thecenter of the plate into which air picked up by the first named bladesin rotation of the plate is discharged radially of the plate.

3. A rotary fan comprising a plate attachable at its center to arotatable element at a right. angle thereto and having aperturessubstantially radially disposed and equi-distantly spaced about thecenter, a blade struck outwardly to one side of the plate and extendingfrom each aperture on one side of the plate at an angle thereto, and acurved blade having a straight edge attached to the plate at the edge ofthe aperture from which the first named blade extends, said curved bladeextending outwardly from its respective aperture on the opposite side ofthe plate from which the first named blades extend and having an openside into which air picked up by the companion angularly disposed bladeblows and is discharged thereby radially of the fan.

4. A rotary fan comprising a plate attachable at its center to arotatable element extending at a right angle thereto and havingequi-distantly spaced V shaped apertures extending from adjacent theperiphery toward the center, the rear edge of the apertures each beingtangent to acircle having its center at the center of the rotation ofthe plate, a pair of blades extending outwardly from opposite sides ofthe plate adjacent the rear edge of each aperture, the blades on oneside of the plate being inclined to the plate and extending forwardly inthe direction of rotation, and the companion blades on the opposite sideof the plate each being of the form of a half-cone with the smaller endtoward the center of the plate and into the open side of which air isdischarged by the first named inclined blades and from the larger end ofwhich air is discharged radially of the plate.

5. A rotary fan comprising a plate of circular form adapted at itscenter for attachment to a rotatable element extending at a right anglethereto, a series of blades struck outwardly from the surface of theplate and extending at an angle thereto on one side thereof andproviding V shaped openings therein, a second series of blades on theopposite side of the plate each consisting of a sheet of materialattached at one edge to the edge of the opening from which the firstnamed blades extend and being curved in form, the free edges of bothblades extending forwardly in the direction of rotation of the plate.

6. A rotary fan comprising a sheet metal plate of circular form adaptedfor attachment at its center to a rotatable element extending at a rightangle thereto, a series of blades formed by portions of the plate struckoutwardly from one face thereof to provide a free edge inclined to theplate surface from the rear of the opening forwardly in the direction ofrotation of the plate, a second series of blades formed of sheet metalhaving a base portion attached to the opposite face of the plate at thebase of the inclined blades and extending rearwardly and thenceforwardlyto form a curved surface providing a blade having substantiallythe form of a half-cone, the small end of which is toward the center ofthe plate, both the said blades being of greatest width at their outerends and providing a means for causing the air picked up by theangularly disposed blades in the rotation of the plate to dischargeradially of the plate in increasing volume from the inner end of thearmate blade toward the outer end.

PERCY WAREHAM.

